Mercurial SCM - Mercurial is a free, distributed source control management tool.
Jenkins - Jenkins is an open-source continuous integration server with 300+ plugins to support all kinds of software development
Sturdy - Simple & efficient code collaboration.
CircleCI - CircleCI gives web developers powerful Continuous Integration and Deployment with easy setup and maintenance.
Git - Git is a free and open source version control system designed to handle everything from small to very large projects with speed and efficiency. It is easy to learn and lightweight with lighting fast performance that outclasses competitors.
Travis CI - Focus on writing code. Let Travis CI take care of running your tests and deploying your apps.